Microscale gas chromatography
Microscale gas chromatography is a separations technique that offers the potential for analyzing volatile organic compounds. Pre-concentration is necessary to concentrate vapors to detectable levels prior to injection into the separation columns. Most devices use a pump to draw air through an absorbent material within the walls of the device, which results in a significant power consumption over a long period of time. Several small-scale devices that utilizes passive, natural processes to draw the vapors into the device, but none have been made on the micron scale. Moreover, these small samplers are only used for collection so far, and analysis is performed separately in a different location.
Passive, microfabricated vapor pre-concentrator/injector
University of Michigan researchers have developed a prototype microfabricated device that captures organic vapors from the atmosphere using diffusion. As such, no external power source is required, allowing for a completely autonomous process. The device is capable of fast, high-throughput performance and has been tested with toluene vapors. It has a low thermal mass and can reach 250°C quickly to allow rapid desorption of gases. Currently, the researchers are continuing to develop this device for processing multiple vapor mixtures and integrating with a micro-column/sensor-array ensemble.
Applications and Advantages
- Chromatographic separations
- Detection of chemical warfare agents
- Natural gas pipelines monitoring and control
- Power source for device is unnecessary
- Portable, cheap, high-throughput gas sensors